Electric-motor control.



' R. FULL R; ELEGTRIG MOTOR GONTROL. APPLIOATIOK FILED EP'1'.9,.1908.

994,993, Patented June 13, 19-11.

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w! TNESSES: 'IM ENTOR 919M541 flhwflm Rodolphns Fuller ATT RNEYS I R. FULLER. ELECTRIC MOTOR CONTROL.

APPLICATION FILED SEPT. 9, 190B.

Patented June 13, 1911.

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CZ 0%. 19M

AT T NEYs nonexistence FULLER, on careers, MICHIGAN.

ELECTEIC-IHO TOR CGTSETROL.

Specification 01 Letters Eatent. Yatggytgd June 13, 1911,,

Application filed September 9, 1908. Serial No. 52,210

' may concern: it known that I, RoooLrHos Frame, a zen of the United States of America, re- 'ng at Detroit, in the county of Wayne ad State of Michigan, have invented ceri new and useful Improvements in Elec- 3?; c-Motor'Control, of which the following a specification, reference being had thereni to the accompanying drawings.

This invention relates to a system of elec motor control which is capable of general application in electric power transmis sion mechanism where great flexibility is required in starting and stoppin with heavy and it is particularly app icahle to the control of electric power trucks, tramways and the like designed for transporting heavy loads and which are driven by electric power enerated on the vehicle itself and transe endent rectors suitable drivi r f contion therewith. v

lily invention involves the rise of a special "enerator driven at a constant speed by an internal combustion engine or other prime mover and'adap'ted to o oerate the motors at ions power output and a controlling switch arranged to increase or decrease'the MD of the generator with each connection in a manner adapted to roduce the n. host efficiency oi the motors in stopping, st 'ing or accelerating. the vehicle and the driver absolute control over the all as more fully hereinafter described l shown in the accompanying drawings Figure 1 represents my invention in (ii 5, 6, 7 an 8 represent the arniatures and.

9, 10, 1-1 and 12 represent the field windings of four series motors C intended to supplied. with current from the 'generz and supposed to be in suitable drive con nection with the four wheels of the vehicle.

13 to 19 represent a series fixed contact lingers in electrical connection. with the hector arise-three, 243 to i; e

:ted to the wheelsof the vehicle through series of fixed contact fingers electrically connected with the terminals of the field windings of the electrical motors.

represents a fixed contact finger forming one of the terminals of the main circuit of the generator.

3l-39 represent a series of fixed contact fingers electrically connected to difierent points of the series field winding ofthe generator, the finger 31 being also elec trically connected to the remaining terminal of the motor field winding 12.

. form of a drum controller, having a suitj able lever handle for turning it and carrying the movable contact strips with which the fixed contacts are adapted to be variously connected by rotating the drum as in the 1 usual construction of s ichdrurn controllers. I The arrangement of these movable contacts is as follows:-The contact fingers 31 to 39 cooperate with a movable contact strip which is gradually stepped off three times in succession so that by revolving the drum from the position shown, in the drawing,

which represents its initial or 0E position,

; one after another of the contact fingers is ,hrought out of electrical contact therewith 1 three times in succession with the exception of the contact 31 which always remains in electrical connection therewith. A similar contact strip is arranged to simultaneously cooperate with the contact fingers 40-47 only this contact strip is reversely stepped off so that in rotating the drum from the initial position one after another of these contact fingers is brought into electrical contact with the strip three times in succession. I

The contact fingers 31-47 being electrically connected as shown and described, the movement of the controller handle in revolving the drum will therefore in start- 111g from the position gradually cut in the sense field winding of the generator'and ;oorre-:

spondingly cut out the shunt resistance iio nect the armatures and fields of the tour motors in series with each other and as there is also "a contact 52 on the drum for the fixed contact 13 which is electricallyconnccted with the strip 50, the motors will be.

its normal speed. .The connection of the ,motors into the generator circuit is eltected 1n the usual manner by means of contact strips 5360 on the controller, these contact strips being electrically divided into three groups I, II, III, the group I etl'ecting the connection thereof in series, group II in parallel series and group III in parallel, all of which is well understood.

The parts being arranged and constructed as shown and described they are intended to operate as follows :-In the otl' position as shown in the drawings the motors are short circuited upon themselves and it the vehicle should be going down hill and in stopping they will therefore assist the action of the brakes. In revolving the drum from this ofi position the motors will connected into the generator circuit and during the first third of the revolution the connection will. be in series, during the second third it will be in series parallel and during the remainder it will be in parallel. At the same time it will be seen that as each connection is made the voltage of the generator is'at zero and only gradually increases to its maximum by the gradual cutting in of the field winding of the generator and the gradual cutting out of the shunt resistance and before and during the change from one connection to another the generator drops back to zero voltage. By revolving the drum thus to the end of its first running position the maximum. torque is obtained for starting and after turning it to the end of its third running position the maximum acceleration is obtained. It is obvious that the connection in parallel series may be omitted without changing the scope of the invention. In order to reverse the motion of the vehicle, a reversing switch 61 is placed in the motor connections, the operation of which is well understood.

What I claim as my invention is 1. The combination with a plurality of series motors utilized for vehicular propulsion, of a generator driven at a constant speed by a prime mover on the vehicle itself and provided with series and shunt field windings, an external resistance in the generator shunt, and a controlling switch having contacts and connections adapted to successively connect the motors in diflerent circuit relations with the main circuit of the scenes generator in moving the controller from its oil position to its full speed position, and to maintain each of such connections for a portion of its travel into such position, and other contacts and connections adapted to gradually cut in the series field winding of the generator and correspondingly cut out the shunt resistance for each portion of such travel.

The combination with a plurality of series motors, of'a generator provided with a series field winding and with a shunt field winding which is always in. circuit, an exter nal resistance in said shunt circuit, and a controlling switch having contacts and connections adapted to short circuit the motors in series with themselves in its off position and to connect them in different circuit relations with the main circuit of the generator when said controller is moved from said position to its full speed position, the controller being adapted to maintain each of saidconnectionsfor a portion of its travel and other contacts and connections adapted to gradually cut in the series field winding of the generator and correspondingly cut out the shunt resistance for each such portion of its travel.

3. The combination with a plurality of series motors, of a generator driven at a constant speed and provided with a graduated series field winding and with a shunt field winding which is always in circuit, an external graduated resistance in. said-shunt circuit equal to the shunt field winding and a controlling switch having constant end connections adapted to short circuit the motors in series on themselves in the oil? positions of the controller and to successively connect the motors in ditl'erent circuit relations with the main circuit of the generator in moving it from said. position to its remote full speed position, the controller being adapted to maintain each of said connections for a. portion of its travel, and other contacts and connections adapted. to gradually cut in the series field winding and correspondingly cut out the shunt resistance for each such portion of its travel.

a. The combination with. a plurality of series motors, of an engine driven generator having both shunt and series field windings, an external resistance in the shunt equal to said shunt field winding, and a controlling switch having contacts and connections adapted to connect the motors in circuit with themselves in its ofi position and to suc cessively connect the motors in different circuit relations with the main circuit of the generator when moved from its off position to its full speed position, the controller being-adapted to maintain each of .said c0n-, ,nectlons for a portion or its travel, and

other contacts and connections adapted to first gradually cut in the series field windassess Winding, and a series parallel controller having contacts and connections adapted to connect the motor elements in difierent cir-' cuit relations With the main 'circuit of the generator in moving the controller from its ofi position through successive steps to a position remote therefrom to gradually increase the output of the generator'froni zero voltage toits maximum on passing through each of said steps and to maintain said voltage at zero While passing through. the position intermediatesaid steps and in the off position of the controller With the generator running at its normal speed In testimony whereof I afiix my signature.

in presence of two Witnesses.

.nononrn'us FULLER.

Witnesses: 4

O'r'ro F. BART IEL, C. R. STIGKNEY. 

